Ignition spark timer and controller for internal combustion engines



June 26, 1934. Q NQXON ET AL 1,964,132

IGNITION SPARK TIMER AND CONTROLLER FOR INTERNAL COMBUSTION ENGINES Filed Aug. 22, 1933 2 Sheets-Sheet 1 INVENTORS: dw'les firlee Nmn $111710 fiz'l flax n ATTORNEYS.

June 26, 1934. Q L, NOXQN ET AL 1,964,132

IGNITION SPARK TIMER AND CONTROLLER FOR INTERNAL COMBUSTION ENGINES Filed Au 22, 1935 2 Sheets-Sheet 2 ATTORNEY5.

Patented June 26, 1934 UNITED STATES PATENT OFFICE Charles Per Lee Noxon and Mills Per Lee Noxon, Syracuse, N. Y.

Application August 22, 1933, Serial No. 686,262

8 Claims.

This invention relates to ignition spark timers and controllers for internal combustion engines, and particularly to ignition systems wherein the spark is created by an induction coil at the time of separating of the contacts of a circuit breaker, and has for its object a particularly simple and eflicient mechanism for automatically determining the time of the breaking of the circuit by the circuit breaker to cause the spark, that is,

m the automatic advancing and retarding of the timer, and also for maintaining the length of time, or dwell, substantially constant at all engine speed that the contacts of the circuit breaker are in contact or closed, so that the spark coil of the ignition system will at all engine speeds, have the same time element of current flow to become energized.

It further has for its object, a mechanism for this purpose including centrifugally operated levers which shift, during changes of the engine speed, to advance or retard the spark in accordance with the speed of the engine, and at the same time shorten or extend, in accordance with the speed of the engine, the time the contacts 5 remain separated, and hence effect a constant time element, at all speeds of the engine that the contacts are engaged.

It further has for its object, a spring means acting to resist the centrifugal action of the levers,

which spring means is common to all of the levers.

It further has for its object, a means for automatically changing the leverage between the spring means and the centrifugal levers to com-' pensate for increases in centrifugal force as the engine speed increases, and for variations in the spring as it becomes tensioned, it being understood that the centrifugal force is proportional to the square of the speed and therefore, the force of spring must be transferred through an 40 increasing leverage, as the speed increases and the spring becomes stiffened.

It further has for its object, a particularly simple connection between the levers and the spring, and the assembly, or arrangement, of the levers and the spring means, in the timer head.

The invention consists in the novel features and in the combinations and constructions hereinafter set forth and claimed.

In describing this invention, reference is had to the accompanying drawings in which like characters designate corresponding parts in all the views.

Figure 1 is a plan view of this timer with the distributor cap removed.

Figure 2 is an isometric, exploded view of parts seen in Figure 1.

This ignition spark timer, or controller, comprises generally, a shaft, a head mounted concentric with the shaft and rotatable thereby, a circuit breaker carried eccentric to the axis of the rotating head, and having members, or arms, 0 provided with contacts, one of which members is movable to separate the contacts, a stationary head carrying the circuit breaker and centrifugally operated means carried by the rotating head and coacting with a wiper on the movable mem- 55 her of the circuit breaker for automatically advancing and retarding the spark, or the instant that the contacts separate and also automatically maintaining the electrical dwell period, or the time the contacts are engaged, substantially constant at all speeds of the engine, or the timer shaft.

l designates the timer shaft, which, as will be understood, is connected to the crank shaft of the engine, in any suitable manner, to be actuated thereby.

2 is a head, or disk, mounted concentric with the shaft 1 and actuated thereby, and here illustrated as rotatable with the shaft 1.

3 and 4 designate the members, or arms, of 30 the circuit breaker carried by a non-rotatable head or disk 5 mounted on the shaft 1 above the disk or head 2, so that the circuit breaker is stationary.

The shaft 1 extends through the head 5 and has a distributor arm 6 at its upper end which wipes over contacts carried by the usual distributor cap, not shown, the contacts of the cap being connected, by wire, to the respective spark plugs of the engine, as will be understood by those skilled in the art. Each member 3, 4, of the circuit breaker is provided with contacts 8 and 9 respectively, and the movable member 4 is also provided with a follower or wiper 10 for coacting with the centrifugal levers to cause the contacts 8 and 9 to break and to make contact.

' 10 designates the hinged clips, or catches, for holding the distributor cap. These catches are on a stationary housing H of the usual construction. The shaft 1 and head 2 rotate in the housing, and'the head 5 is stationary within the housing. The distributor cap, not shown, is mounted on the housing H in the usual manner. The spark may be manually retarded, or advanced, inany well known manner.

11 designates a circular series of centrifugal levers pivoted at 12 to the rotatable head 2 and movable in an orbit about the circuit breaker, each of the levers being provided with a surface 13 on its inner side coacting with the wiper 10.

The pivot of each lever is located near one end providing short and long arms, the long arms being of such weight as to cause the levers to swing outwardly under the centrifugal force, and thus change the relative position of the surfaces 13 to the wiper. When the engine is running at low, or lowest speed, these surfaces 13 are located in the path of the follower or wiper 10 so that the spark is retarded to its greatest extent, and the wiper 10 engages the faces 13 substantially throughout the length thereof. Or, during the low or lowest speed, each lever 11, or surface 13 thereof, engages the wiper 10 at point A and moves out of engagement therewith to point B, and the time element, or electrical dwell period during the lowest speed is while the wiper 10 is between point B of one lever and the point A of the next succeeding lever of the series.

As the engine speed increases, and the centrifugal levers 11 are thrown outward, the short arms thereof are moved slightly inwardly so that point C of each lever first engages the wiper 10 and advances the spark, and the lever moves out of engagement with the wiper at point D, so that the electrical dwell period, or the time element that the contacts 8, 9 are engaged occurs while the wiper 10 is between the point D of one lever and the point C of the next succeeding lever. The point D shifts nearer the axis of the lever, and the point C farther from the axis of the lever, as the speed increases. However, the actual time element between the point B of one lever and the point A of the next succeeding lever is always the same as the time element between any point D of one lever and any point C of the next succeeding lever.

The spring means, common to all the centrifugal levers for yieldingly resisting the outward throw thereof and for changing the leverage of the spring on the lever as the speed varies, comprises a spring 15 secured to the head 2, and motion transmitting means including a differential lever between the other end of the spring and the centrifugal levers 11. This motion transmitting means includes a radial arm 17 on each of the levers 11, a coupling member as a collar 18 about the shaft 1 and common to all the levers serving as an equalizer between the levers, a coupling pin 19 here shown extending from one of the lever arms 1'7 through the head 2 to the lower side thereof, and the differential levers between the pin 19 and the spring 15. The pin 19 extends through a slot 2 in the head 2 to permit relative turning movement of the collar and the head 2 during centrifugal movement of the levers 11, and pivotal movement of the differential lever.

As here shown, the collar is capable of rotating, within limits, about the shaft 1 relatively to the head 2. However, any motion between the collar and the head 2 is relative only, and it is immaterial whether the collar is fixed to the shaft and the head 2 capable of rotary movement, within limits, relatively thereto, or the head 2 fixed to the shaft and the collar rotatable about the shaft, within limits. As the operation would be the same, except that the short arms of the centrifugal levers would be of slightly different shape, or might not be as long, or might be omitted for the reason that in this case, the levers advance bodily, while in the construction shown herein, the head 2 is fixed to the shaft, the short arms of the levers are brought inwardly as the speed increases in order to advance the spark.

The radial arms 17 are fixed to the levers in any suitable manner, and may be integral there with. As here illustrated, there are separate pieces for the levers, with an angular portion 1'7 at the outer ends of the levers which are secured to the levers 11 at the pivots thereof at 1'7 to the levers.

The differential mechanism between the centrifugal levers 11 and the spring to increase the leverage of the spring, as the differential levers fly outward and decrease as they move inward, comprises a cam lever 21 pivoted at 22 on the under side of the head 2 and connected by the pin 19 to the collar 18, and having a cam face 23 and a follower lever 24 pivoted at 25 to the under side of the head, and having its free end engaging the cam surface 23, the spring 15 being anchored at one end at 26 to the head, and at its other end at 27 to the free end of the lever 24. The pivot 22 coaxial with one of the levers 11 and is an extension of the pivot of one of the levers l1.

At lower speeds, the follower lever engages the cam surface 23 at a point toward or near the pivot 22, the centrifugal levers 11 move outward under the centrifugal force, the differential lever 21 moves in the direction of the arrow (Figure 2) about its pivot 22, owing to the coupling of the radial arm 17 of one of the levers with the pin 19. and in so moving, shifts the cam lever so that the end of the lever 24 engages cam lever at a greater distance from the pivot 22, thus increasing the leverage of the spring on the contrifugal lever and compensating for the increase, or acceleration, of the centrifugal force the speed increases, so that the dwell period of the timer, or the period that the contacts of the circuit breaker remain engaged, remains constant at all engine speeds.

Although we have shown a timer for a four cylinder engine, obviously it is equally well adapted to six, eight, twelve and sixteen cylinder engines. For an eight cylinder engine, two circuit breakers, and two coils would be sed. For a twelve, six centrifugal levers would be used with two circuit breakers and coils, or a timer with four levers, as shown, and three circuit breakers and three coils used. With a sixteen cyiin der, two series of levers with four levers in each series, and two circuit breakers for each series. In a six cylinder engine, three levers may be used, and two circuit breakers, and two coils.

What we claim is:

l. A spark timer and c 'oller ignition systems comprising a shalt, a h and rotatable thereby, a circuit l tionary carrier therefor, the biea including a movable arm operable to sep; ate the contacts of the breaker, a series of spec apart centrifugal levers pivoted to the head and having long and short arms on opposite sides of their pivots, the circuit breaker contacts being located within the circle of t': series of lovers and the movable breaker lever having a n per for engaging the inner faces of the centrifugal levcrs, and spring means for resisting the out ward throw of the 152E413 under the centrifugal force, all whereby the wiper engages each lever to separate the contacts of the breaker, and the effective surface on the centrifugal levers, with which the wiper engages, varies as the speed of the head varies.

2. In a spark timer and controller for ignition systems, a shaft, a head mounted on the shaft and rotatable thereby, a circuit breaker 1ncluding contacts and a movable member operable to separate the contacts, a stationary support for the breaker, a series of centrifugal leer, a stavers carried by the head, the circuit breaker extending within the circle of the series and having a wiper for engaging the inner faces of the levers, and spring means common to all of the levers for resisting the outward throw of the centrifugal levers under the centrifugal force.

3. In a spark timer and controller for ignition systems, a shaft, a head mounted on the shaft and rotatable thereby, a circuit breaker including contacts and a movable member operable to separate the contacts, a stationary support for the breaker, a series of centrifugal levers carried by the head, the circuit breaker extending within the circle of the series and having a wiper for engaging the inner faces of the levers, and spring means common to all of the levers for resisting the outward throw of the centrifugal levers under the centrifugal force, and means for automatically varying the effective force of the spring on the levers in accordance with the speed of the shaft.

4. A spark timer and controller for ignition systems comprising a rotary shaft, a head mount-- ed on and rotatable by the shaft, a circular series of centrifugal levers, each having long and short arms carried by the head concentric with the shaft, a circuit breaker within the circle of the series of levers and having a movable member operable to separate the contacts of the breaker, said movable member having a wiper engaging the inner faces of said levers, a stationary support for the breaker, spring means for resisting the outward throw of the levers under the centrifugal force, and means controlled by the speed of the shaft for increasing the effective force of the spring means on the levers as the speed and centrifugal force increases, all whereby the time element required for the wiper to pass out of engagement with the inner face of one lever into engagement with the inner face of the next lever remains substantially constant at all speeds of the shaft and the head.

5. A spark timer and controller for ignition systems comprising a shaft, a rotating head on the shaft and actuated thereby, a stationary head, a circuit breaker carried by the stationary head and including members having contacts, one of the members being movable to separate the contacts, a series of centrifugal levers carried by the rotating head concentric with the shaft, the breaker being located within the circle of the series and the movable member of the breaker having a wiper coacting with the inner faces of the levers, a spring common to all of the levers for yieldingly resisting the throwing out of the levers under centrifugal force, and means for causing the spring to act on the levers equally and proportionally as the speed increases.

6. A spark timer and controller for ignition systems comprising a shaft, a collar member and a head member mounted on the shaft in concentric relation, one of said members being fixed to the shaft to rotate therewith and the other to rotate, within limits, relatively to the shaft, a stationary head, a circuit breaker carried by the stationary head and including a fixed and a movable member having coacting contacts, the movable member being operable to alternately separate and engage the contacts, a series of centrifugal levers carried by said rotating head member concentric with the shaft, said levers having long and short arms and the circuit breaker extending within the circle of the series and having a wiper for coacting with the inner faces of the levers, each of the levers having a radial arm rigid therewith and connected to the collar member, and spring means for resisting the outward throw of the centrifugal levers under the centrifugal force.

7. A spark timer and controller for ignition systems comprising a shaft, a collar member and a head member mounted on the shaft in concentric relation, one of said members being fixed to the shaft to rotate therewith and the other to rotate, within limits, relatively to the shaft, a stationary head, a circuit breaker carried by the stationary head and including a fixed and a movable member having coacting contacts, the movable member being operable to alternately separate and engage the contacts, a series of centrifugal levers carried by said rotating head member concentric with the shaft, said levers having long and short arms and the circuit breaker extending within the circle of the series and having a wiper for coacting with the inner faces of the levers, each of the levers having a radial arm rigid therewith and connected to the collar member, and spring means for resisting the outward throw of the centrifugal levers under the centrifugal force, said spring means being carried by the rotating head member, and a differential lever operable by the centrifugal levers for transferring the force of the spring to said radial arms.

8. A spark timer and controller for ignition systems comprising a shaft, a rotating head on the shaft and actuated thereby, a stationary head, a circuit breaker carried by the stationary head and including members having contacts, one of the members being movable to separate the contacts, a series of centrifugal levers carried by the rotating head concentric with the shaft, the breaker extending within the circle of the series and the movable member of the breaker having a wiper coacting with the inner faces of the levers, a spring common to all of the levers for yieldingly resisting the throwing out of the levers under centrifugal force, an equalizing member common to all of the centrifugal levers and to which each of the levers is connected, a 

